Fabric manufacturers want to know as much as possible about entangled yarn before it is used to manufacture fabric or other products. If the yarn does not have desired properties, there can be problems with a fabric production process as well as in a finished product made from the yarn. Some fabric manufacturers may specify yarn properties (e.g., to yarn producers), and the yarn producers may strive to provide yarn with such properties. In order to ensure that yarn has specified properties, the yarn producer may analyze and test the yarn for the properties.
Properties of entangled yarn include entanglement count and entanglement integrity or strength. Quality grade entangled yarn includes one or more entanglements and one or more skips. An “entanglement” refers to a section of yarn in which filaments are tightly intermingled as a result of passing through an entanglement jet of a texturizing machine. A “skip” refers to a section of yarn which is not intermingled and which is found prior to and after each entanglement. A good quality yarn, therefore, should have an equal, consistent, and predictable number of entanglements. The entanglement strength is another property of entangled yarn and is a measure of how strongly the entanglements are held in the yarn. As an indication of strength, entangled yarns are sometimes defined as “soft-entangled” and “hard-entangled,” with the soft-entangled referring to entanglements that are easily removed from the yarn when the yarn is under tension and the hard-entangled referring to entanglements that are very resistant to removal.
Entanglement jets come in a variety of sizes, shapes, and designs that attempt to produce entanglements in yarn. The entanglements result from the air blast in the center of the jets (e.g., which causes the yarn filaments to spread) and from the yarn filaments on either side of the air blast winding themselves together. The end result after passing through an entanglement jet should be an even distribution profile of entanglements along the yarn. However, when entanglements are unevenly distributed, there are large skips between the entanglements.
If a distribution profile of yarn entanglements is inconsistent, properties of a fabric manufactured with the yarn may be inconsistent. For example, such fabric may have inconsistent reflectivity, which may cause different portions of the fabric to have different colors when dyed. Therefore, it is desirable to quantify and measure yarn entanglement properties in the lab in order to control such properties. For example, if a yarn is determined (e.g., via testing) to have an inconsistent distribution profile of yarn entanglements, the yarn manufacturer may alter process parameters (e.g., via changes to the entanglement jets being used) to improve the distribution profile of yarn entanglements.
The entanglements act to prevent individual filaments from flaring-out, spreading, or separating during processing of the yarn into a fabric, thereby maintaining a cohesive yarn bundle of filaments. The strength of an entanglement is related to its resistance to open or to remove the entangled sections of the yarn when under tension. Entanglement strength is a key element in beaming, knitting, and weaving performance of an entangled yarn. During the beaming process, tension is applied to the yarn which tends to cause the entanglements to pull out or became unraveled. Moreover, as beam yarn is supplied from the beam to a weaving or knitting machine the yarn again is subjected to tension. The fabric production performance is most affected by the knitting machine or weaving loom having to stop frequently because the individual yarn filament strands experience breaks or separation of the filaments due to a loss of entanglements in the yarn. Proper entanglement strength may result in a yarn that will be able to achieve highly efficient beaming, knitting, and weaving performance.
The distribution profile of yarn entanglements is currently tested via manual strength testing of the yarn entanglements. The manual strength test includes manually counting the number of entanglements that are in the yarn as taken from a bobbin or cone. After counting, a draw tension or tensile force is manually applied to the yarn, in an attempt to elongate the yarn and open or remove the entanglements in the yarn. Then the yarn is relaxed and a second manual count is made to determine how many entanglements remain in the yarn at the particular draw tension/tensile force. Some entanglements will be removed by the tensile force and some will not be removed. If a greater tensile force is applied to the yarn, even more entanglements will be removed from the yarn. However, such manual methods are time consuming and may lead to inaccuracies (e.g., due to human error).